A visual impression of a scene and objects and features in the scene is generally a function of illumination of the scene. Objects in a scene that are illuminated so that they contrast strongly with their local background tend to capture our attention. Acuity with which the eye is able to distinguish details of features in a scene and impressions of features of a scene are generally dependent upon the power spectrum of light illuminating the features. For example, color of a woman's dress and her fashion accessories may appear harmonious in one light and discordant in another light. In addition, cultural convention has coded color with information that affects our reason and emotions and these cultural conventions affect the way colors in a scene generate responses to the scene. Red, yellow and green lights not only tell us when to stop at traffic lights but also, alert our reason and emotions to various degrees of danger, or lack thereof.
It is therefore seen that when illuminating a scene for a particular desired application, generally many different variables have to be considered and taken into account. As a result, achieving effective illumination of a scene is often a relatively complicated, subtle and arduous task.
U.S. Pat. No. 5,828,485 describes an illumination device for stage lighting comprising an image source that acquires an image of an actor on a stage and an array of digital micromirrors for directing light from a suitable light source to the stage. The array of micromirrors is controlled responsive to the image of the actor to project different shape and color light beams for illuminating the actor. The illumination device is controllable to follow the actor as he or she moves on the stage and illuminate the actor accordingly. The patent notes that characteristics of the projected light beam, e.g. its shape and color can be controlled by “image processing software such as Adobe photoshop™, Kai's power tools™ and the like”.
U.S. Pat. No. 4,501,961 describes a range finder having a photosurface for imaging an object, whose distance from the range finder is to be determined, and an array of LEDs for illuminating the object. To prevent parallax, light from the array of LEDs is focussed on the object by a same lens that collects light from the object and focuses the collected light on the photosurface. A controller controls the array of LEDs to illuminate the object with a pattern of light which when imaged on the photosurface provides information for determining range to the object. The range finder comprises a negative lens to adjust the size of the illumination pattern to the size of the photosurface.